A mobile computing device such as a combination handheld computer and mobile telephone or smart phone generally may provide voice and data communications functionality, as well as computing and processing capabilities. In some cases, a smart phone may support communication over a Global System for Mobile Communications (GSM) network. In general, four frequency bands are used by most GSM mobile computing devices: the 850 MHz frequency band (GSM-850), the 900 MHz frequency band (GSM-900), the 1800 MHz frequency band (GSM-1800), and the 1900 MHz frequency band (GSM-1900), as defined by the European Telecommunications Standards Institute (ETSI).
In the United States, Canada, and many other countries in the Americas, GSM-850 and GSM-1900 are used for GSM service. In most international countries, however, GSM-900 and GSM-1800 are used for GSM service. A GSM mobile computing device may be configured to operate using only certain frequency bands such as GSM-850 and/or GSM-1900, if sold in the United States for example. While the 850 MHz band is close to the 900 MHz band and the 1900 MHz band is close to the 1800 MHz band, a mobile computing device configured to work using only GSM-850 and/or GSM-1900 will not work in the 900 MHz frequency band or the 1800 MHz frequency band. As a result, the mobile computing device of an international traveler often may be incompatible with the frequency band or frequency band pair used at the destination.
Many frequency-compatibility problems may be avoided through the use of a multi-band mobile computing device that supports background scanning and switching among different frequency bands. Supporting multiple frequency bands, however, may result in long delays, high roaming charges, and/or device lock-up when searching for an available or preferred frequency band. Accordingly, there exists the need for an improved apparatus and methods for providing multi-band operation in a mobile computing device.